Rotary printing machine

ABSTRACT

A rotary printing machine for printing designs the pattern of which is repeated and which is printed by at least two rotating printing cylinders. Each cylinder is adapted to be brought temporarily out of contact with the material to be printed. Means are provided for moving each of the cylinders and the material relative to each other, and each such means is activated by a digital counting device having memory capabilities after a preset number of impulses, such number depending on the angle of rotation of the respective cylinder.

United States Patent Zimmer ]*Nov. 25, 1975 [5 1 ROTARY PRINTING MACHINE3,139,025 6/1964 Chambon 101/182X ,19 ,4 1. 101 184 1 1 Inventor: Peter11mm", were Sparchen 54, 3223 03-? 11322 5232123213.? 1011172 KufstemAusma 3,291,044 12/1966 Van Der Winden 101/118 1 Notice: The portion ofthe term of this big giis ig 18 fg z gi to ,SePL 3,359,893 12/1967 Zahnet a1 101/218 x een lsclalmed- 3,467,007 9/1969 Stotzeret 31.... 101/184x 22 Filed; June 11 1974 3,503,232 3/1970 Farrer et a1 101/172 3,527,1649/1970 Buck 101/184 X [21] Appl. No.: 478,388 3,587,458 6/1971 Feier,101/120 3,774,533 11/1973 lchinose. 101/119 Related Applcamn D 3,834,3099 1974 Zimmer lOl/ll6 [63] Continuation-in-part of Ser. No. 304,935,Nov. 9,

1972 abandoned Primary Examiner.1. Reed Fisher Attorney, Agent, orFirmWenderoth, Lind & Ponack [30] Foreign Application Priority Data Nov.15,1971 Austria 9818/71 [57] ABSTRACT 52 us. c1. 101/116; 101/181;101/182 A rotary i machine for Prim/31188191151116 [51] Int Cl 2 H 5/06tern of wh1ch 1s repeated and whlch 1s printed by at [58] Field ofSearch 101/11s-120, least two mtatmg Prmmg f Each l01/178 181 182 185248 adapted to be brought temporarily out of contact with the materialto be printed. Means are provided for [561 83:21 2112321: 211113 212121: 1128;121:315

, u UNITED STATES PATENTS digital counting device having memorycapabilities JBOUIB after a preset number of impulses such numberdeattey... 3 13 2,573,097 longs] Epstein 01/172 UX i iletecimg on theangle of rotat1on of the respectwe cyl 2,663,256 12/1953 Chamb0n..101/228 I 2,893,310 7/1959 Johnson 101/182 8 Claims, 8 Drawing FiguresOUTPUT LOAD COUNTER US. Patent Nov. 25, 1975 Sheet10f4 3,921,519

F/a. 3b

US. Patent Nov. 25, 1975 Shset 2 of4 3,921,519

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OUTPUT 9O 93 7 9O 85 PRESET LOAD 9| I (Bf FLIP-FLOP 86 U.S. Patent Nov.25, 1975 Sheet4of4 3,921,519

ROTARY PRINTING MACHINE This is a continuation-in-part of applicationSer. No. 304,935, filed Nov. 9, 1972, now abandoned.

BACKGROUND OF THE INVENTION SUMMARY OF THE INVENTION It is an object ofthe invention to provide a printing machine which renders it possible toprint long repeated designs by using relatively small printingcylinders, these printing cylinders being adapted to sequentially bebrought temporarily out of contact with the material to be printed.Thus, each cylinder prints only part of the total repeated pattern, andthe various cylinders cooperate to print the whole repeated pattern ordesign.

In order to ensure correct timing of the lifting and lowering of thecylinders away from and toward the material, as well as the precisecombining of the various parts of the pattern printed by each cylinder,the invention further proposes to provide a digital counter de vicehaving memory capabilities for each cylinder which activates the meansfor lifting and lowering each cylinder after a preset number ofimpulses, such number depending on the angle of rotation of each of therespective cylinders. Thus the speed ratio of the different gears of themachine is of high importance in order to obtain the correct movement ofthe cylinders or the material in accordance with the desired pattern.

Theimpulses conveniently are taken by tooth detecting means, such asoptical or inductive devices, from a toothed disc fixed, e.g., on thedrive shaft for the cylinders.

The present invention is hereinafter described with reference to arotary screen printing machine to which it is particularly suitable. Theinvention, however, is not limited to this specific type of machine butmay be applied to all machines having rotary printing cylinders, e.g.,to machines using roller printing, photogravure printing, etc.

In accordance with a preferred embodiment of the invention involving arotary screen printing machine, the printing machine includes a printersblanket tensioned between two guide rollers, one of which is driven andmoves the printers blanket, which in turn drives the other guide roller,the rotation of which is' transmitted to a main device shaft by meanssuch as bevel gears and a universal-joint shaft. The main drive shaftextends through transmission devices for each A toothed disc is fastenedto the end of the main drive shaft, and has a number of teeth equal toor a whole multiple of the number of teeth of each drive gear. A toothdetecting means such as a photocell arrangement or an inductivetransmitter device registers the presence or passage thereby of eachtooth of the toothed disc and emits one impulse or a whole numberprinting station including screens with Squeegees.

of impulses for each tooth of the toothed disc.

These impulses are transmitted to a digital counting.

device for each screen. Each :such device is set to emit an impulseafter receipt of a predetermined number of impulses from the toothdetecting means, indicative of the exact angular rotation of therespective printing screen or cylinder. Thus, the impulse from eachdevice occurs at a well determined angular position of the correspondingprinting screen, and therefore also at a predetermined point in theoverall repeated pattern. Variation of this predetermined point iseasily achieved by manual addition or adjustment of a desired number ofimpulses.

The printing cylinders are journalled in bearings which are mounted onframes in a known manner and which are lifted by hydraulicpiston-cylinders assemblies, the operation of which. are controlled bymagneto-hydraulic valves in response to the impulses generated by therespective digital counting devices. Thus, on one such impulse therespective printing cylinder is lifted from a position in contact withthe material to be printed, and on receipt of a second such impulseislowered from such lifted position. Therefore, each cylinder rests onthe material for an exactly defined period.

The invention may be used in a machine wherein the length of the overallrepeated pattern is a whole multiple of the circumference of one of thescreens. However, the invention is also applicable to a machine whereinsuch is not the case, that is wherein the length of the overall repeatedpattern is not a whole multiple of the circumference of one of thescreens.

However, in such a case the machine must include means to impart anadditional rotation to the cylinders when they are lifted off thematerial. For this purpose, a supplementary drive shaft may be providedparallel to the main drive shaft, the two shafts being connected bysuitably chosen reduction gears. Both shafts act on sets of screentransmission gears. Each such set may include any suitable means toimpart an additional forward or backward rotation to the respectivecylinder when it is in the lifted position. For instance each set ofgears may'consist of a part: which adds or subtracts rotation to therespective screens and a Maltese-cross drive, or of a differential driveand a storing device for providing a predetermined additional angularmovement.

If such a supplemental drive is provided, it is possible to print arelatively long pattern the total repeated length of which is not awhole multiple of the circumference of the cylinders. This additionalmovement can be freely chosen but is equal for all cylinders. In such anarrangement preferably the impulses which characterize the angularposition of each cylinder are taken individually from each cylinder.

Instead of lifting or lowering the printing cylinders, the contactbetween the latter and the material may also be effected or interruptedby lifting and lowering the transport blanket supporting the material.

BRIEF DESCRIPTION OF THE DRAWINGS The above inventive features will bedescribed in more detail below with reference to the accompanyingdrawings wherein:

FIGS. 1a and lb are respectively a schematic illustration of oneembodiment of a screen arrangement suitable for use of the presentinvention, and a pattern printed by such arrangement; M

FIG. 2 is a detailed illustration of the present invention used with thescreen arrangement of FIG. 1a;

FIGS. 3a and 3b are respectively a schematic illustration of a furtherembodiment of a screen arrangement suitable for use of the presentinvention, and a pattern printed by such arrangement;

FIG. 4 is a detailed illustration of the present invention used with thescreen arrangement of FIG. 3a;

FIG. 5 is a schematic view, partially in section, through one of thescreens of FIG. 4 and the means for imparting rotation thereto; and

FIG. 6 is a partial view of a printing screen station illustrating anarrangement for lowering the transport blanket rather than raising thescreen.

DETAILED DESCRIPTION OF THE INVENTION In the following detaileddescription, reference will be made to perforated cylinder screenshaving therein squeegee devices mounted in a known manner. However, theinvention is not limited to this specific arrangement, but may be usedin other rotary cylindrical printing machines.

FIG. la shows the printing cylinders, such as screen stencils l, 2, 3and 4 which together print an overall repeated pattern on the web ofmaterial 9, whereby the pattern is longer than the circumference of anyone of the screens. The web of material 9 is supported by the printersblanket l0, and the blanket 10 is moved and guided over two guiderollers, one 11 only of which is shown in FIG. la. The printed patternshown in FIG. lb is divided into several partial patterns 5, 6, 7, 8.The partial pattern 5 extends from the dotted line 12 to line 13, thepartial pattern 6 extends from line 13 to line 14, the partial pattern 7extends from line 14 to line 15, and the partial pattern 8 extends fromline 15 to line 16.

Only three quarters of the circumference of each screen 1 to 4 areprovided with a pattern printing portion 17, the remaining 90 portion 18of the circumference being a non-printing portion, i.e., having a wallwithout any perforations. The screen 1 is provided with a printingportion for the part 5 of the pattern, the screen 2 a printing portionfor part 6, the screen 3 a printing portion for part 7, and the screen 4a printing portion for part 8.

In the position of the web shown in FIG. lb, part 5 has already beenprinted by the screen 1, the screen 1 being precisely in the positionfor the beginning of the printing of another part 19 which is identicalwith part 5. Also, screen 2 has already printed part 6 of the pattern onthe material web, the screen 2 being in a lifted position and awaiting acommand for printing another part identical with part 6 which, however,has yet to be conveyed to screen 2. On the contrary, screen 3 is in theprinting position and has printed a portion of part 7. That is, part 7has been printed from line 14 up to the dotted line 20, whereas thesection between lines 20 and 15 has yet to be printed by screen 3.Screen 4 has not yet printed part 8 of the pattern on the material weband is in the lifted position. Screen 4 will be lowered at the momentwhen the trailing end of the nonprinting circumferential portion 18 ofscreen 4 is at the lowermost position of the circumference of thescreen.

To carry out the printing process shown in FIG. 1, the machine isprovided with a control mechanism as shown in FIG. 2. The printingmachine 21 contains the four screens 1 to 4 which are positioned insupports 22 which may be lowered or lifted toward or away from theprinters blanket 10 of the printing machine 21, i.e., into and out ofcontact with material 9. It is of course to be understood that the scopeof the present invention includes machines having a plural number ofscreens less than or greater than four. The lifting and loweringmovement is effected by hydraulic pistoncylinder mechanisms 23, suchlifting movement being limited so as to insure that screen gears 38connected to each screen remain engaged with driving gears 24. Thesedriving gears 24 are driven from a guiding roller 25 of the machine,whereby a main drive shaft 28 is kept synchronized with the movement ofthe printers blanket by means of bevel gears 26 and auniversaljoint-shaft 27. The main drive shaft 28 carries worm or spiralgears 29 which transmit the movement of the main drive shaft 28 to thedriving gears 24. The ratio of the spiral gears 29 are 1:1, andtherefore the rotational speeds of gears 24 and main drive shaft 28 arethe same. In the specific example described the gears 24 have 32 teeth.At the end of shaft 28 is fixed a toothed disc 30 which also has 32teeth. A tooth detecting means 31 such as a light beam-photocell deviceor a proximity detector of the inductive type detects the passagethereby of each tooth of toothed disc 30 and emits an impulserepresentative thereof. Means 31 emits 32 impulses for each revolutionof shaft 28, such impulses being sent to digital counter devices, whichin the illustrated embodiment are counter-relay mecha nisms 33, to bedescribed in more detail below. Since the impulses from means 31 arerather faint, they are amplified by an amplifier 32. Due to theidentical number of teeth on each gear 24 and on disc 30, each impulseof tooth detecting means 31 corresponds to one tooth of gear 24 and alsoof screen gear 38. In the specific embodiment described each of gears 38has 108 teeth.

As stated in connection with FIG. 1, one quarter of the circumference ofeach screen comprises a nonprinting portion, and three quarters of thecircumference of each screen comprises a printing portion. Thus, theprinting portion of the circumference corresponds to 81 teeth of screengear 38, and since each tooth corresponds to one impulse from toothdetecting (and impulse generating) means 31, the printing period (fromthe beginning to the end of the printing portion) for each screen isexactly 81 impulses. On the other hand, the period for the passage ofthe non-printing portion of the circumference of each screen is 27impulses. Thus, each of the partial patterns 5, 6 7 and 8 shown in FIG.1b is equivalent to 81 impulses. The total length of the overallrepeated pattern, i.e., the length of the material web from line 12 toline 16 therefore corresponds exactly to 4 X 81 impulses, i.e., 324impulses. Further, since the total circumference of each screencorresponds to I08 impulses, the total length of the overall repeatedpattern corresponds exactly to three times the circumference of each ofthe screens. It of course is to be understood that these specificexamples of gear teeth and impulses are intended to be exemplary only,and not limiting to the scope of the invention.

The impulses from tooth detecting means 31 are fed to the counter-relaymechanisms 33 via amplifier 32, one assembly 33 being provided for eachscreen. The following description will be with regard to the mechanism33 for the screen 4, the mechanisms 33 for screens 1, 2 and 3 beingshown schematically for the purpose of clarity. To initially set screen4, the web is moved such that line of the pattern thereon lies slightly(e.g., a few cms) before the position whereat printing thereon ofpartial pattern 8 by screen 4 would begin. Then the screen 4 is manuallyadjusted, either by disengaging the gear 38 and turning the screen byhand, or by means of a known type of screen adjusting device which maybe provided at each printing station, such that the beginning of theprinting portion of screen 4 will coincide with line 15 of the materialweb on further movement of the screen and the material web. If exactalignment is not obtained in a first printing pass, exact alignment ofscreen 4 (as well as the other screens) may be achieved by the mentionedknown type adjusting device during subsequent printing passes. However,before continuing to print, A-counter unit 34 of mechanism 33 for screen4 is cleared by a manually instituted clearing impulse in a knownmanner. A preset unit 36 is set to store a predetermined number, in thiscase the number 324. If an impulse is manually applied to the loadterminal 43, the number stored in A preset unit 36 is transmitted to theA counter unit 34.

On further driving of the machine (moving the web) each tooth of disc 30induces an impulse in means 31, and these impulses are fed via amplifier32 to the input terminal 40 of A-counter unit 34. Each of these impulsesdecreases the number contained in A-counter unit 34 by one. After 81impulses partial pattern 8 of the web has been printed and the contentof A-counter unit 34 is 243. A similar setting process is then carriedout for B counter unit 35. B preset unit 37 is also set at the number324. Screen 4 is rotated until the end of the printing portion of screen4 is reached (which may be carried out at a very slow screen rotationspeed), and the machine is stopped. A clearing impulse is manuallyinduced in a known manner into B-counter unit 35 to clear counter 35 tozero. The same impulse goes over line 39 to the load terminal 44 of Bpreset unit 37, and counter 35 is set to the number contained in Bpreset unit 37, i.e., 324. When the clearing impulse mentioned above isfed to the terminal 43 the impulse in line 39 acts on terminal 44 ofpreset unit 37. Thus, counter 35 is loaded with number 324 while counter34 is loaded with number 243.

The assemblies 33 for screens 1, 2 and 3 are similarly initially set, ofcourse however in their respective phase relationship for respectivelyprinting partial patterns 5, 6 and 7.

The machine is then started, and the following takes place (with regardto screen 4).

Each impulse coming from tooth detecting means 31 and fed via amplifier32 to the counters 34 and 35 diminishes each of the numbers containedtherein by one. Counter 34 is the first one which is decreased to zero,and this occurs exactly 324 impulses after counter 34 was set, i.e.,after partial pattern 8 of the material web was starting to be printed.Exactly when counter 34 reaches Zero, the next section of the materialweb which corresponds to partial pattern 8 has arrived at exactly thatpoint where the same is to be printed by screen 4. Now, when counter 34reaches zero it emits at its output terminal 42 an impulse which, on theone hand, is applied to the clearing terminal 45, and, on the otherhand, causes the repetition of the loading process since it is appliedto the terminal 43 of the preset unit 36.

Furthermore, this impulse is fed to the terminal 46 of flip-flop 47which is switched over and emits an impulse from output terminal 48 Thisimpulse is fed via amplifier 49 to a magnetic valve 50 (to be describedin more detail below) which is shifted to cause screen 4 to be lowered,i.e., to move into its printing position.

After a further 81 impulses, counter 35 reaches zero and emits animpulse at its output terminal 51. This impulse is applied to clearingterminal 43 and to load terminal 44 to initiate a new loading process ofcounter 35 via preset 37. Again counter 35 is loaded by the preset unit37 with the number 324, the starting number for a new countdown. Theimpulse leaving terminal 51 is furthermore fed to the input terminal 46of flip-flop 47 which again is switched over, and through outputterminal 48 emits a signal which is transmitted via amplifier 49 tomagnetic valve 50 which is shifted back to the position shown in FIG. 2to cause screen 4 to be lifted. Thus, these alternating commands tovalve 50 are sent based on the numbers of impulses fed intocounter-relay mechanism 33. Emission of these signals takes place aftera predetermined number of impulses, which corresponds to a predeterminedlength of the material web having passed through the machine.

Magnetic valve 50 is connected at its entry 50' to a pump 52 via aconduit 53. In the position shown in FIG. 2 entry 50' is connected toexit 54 of the valve in communication with lower chamber 55 ofpistomcylinder assembly 23. Therefore, the piston together with support22 and screen 4 will be lifted. The upper chamber 56 is connected viaconduit 57 to exit 58 of magnetic valve 50. In the position shown,liquid will flow from exit 58 to entry 59 connected to the collectingpipe 60. Oil contained in chamber 56 will thus be reconveyed intoreservoir 62 via return line 61.

It will be apparentthat the operations of mechanisms 33, valves 50 andassemblies 23 for screens 1, 2 and 3 will operate in exactly the mannerdescribed above, with the obvious exception that each unit will operateat a distinct and predetermined time. That is, each unit will be out ofphasewith the other units. In the specific examples described, thescreens operate sequentially out of phase by 81 impulses in the order of1, 2, 3 and 4.

FIGS. 3a and 3b show an embodiment of the present invention employingtwo printing screens to print an overall repeated pattern, whereinhowever the length 63 of the overall repeated pattern is not equal to amultiple of the circumference of one screen. In the specific example ofFIG. 3, the overall pattern length 63 is not equal to twice thecircumference of screens 64 or 65, which respectively have non-printingportions 66 and 67. Lifting and lowering of the screens of course mustbe effected only when the non-printed portions are in the area ofcontact with material web 68. The latter moves in direction 69 and thescreens rotate in direction 70. Screen 64 is provided with a printingportion for printing partial pattern 71, and screen 64 with a printingportion for printing partial pattern 72. In the position shown in FIG. 3screen 64 has just finished its printing operation and has printedpartial pattern 71 on the material web 68. When the material web hasmoved by the distance 73, the end 74 of partial pattern 71 will arriveunder screen 65 which will be lowered into its printing position withthe trailing edge 75 of the nonprinting portion 67 coinciding with end74. Subsequently partial pattern 72 is printed by screen 65. The patternin this part is shown in dotted lines in FIG. 3b in order to indicatethat, in the position illustrated, it has not yet been printed.

If the material web is provided with a pattern in the manner shown inFIG. 3b, it is possible to print a pattern of a length greater than thecircumference of one screen. However, it must be noted that the overallpattern length 63 is not a multiple of the circumference of the twoscreens but is somewhat shorter than the sum of the circumferences ofthe two screens. This means that the end of one overall pattern, or thebeginning of a new partial pattern to be printed by screen 64, will notalign with the leading end 76 of the printing portion of screen 64 ifscreen 64 is always rotated in synchronization with the material web.Therefore, it is necessary to take steps to insure such properalignment.

According to the invention, an adjusting movement is imparted to thescreen 64 during the period in which it is in the lifted position. Inother words, after the screen 64 has printed partial pattern 71 andsubsequently has been lifted, an additional rotational movement isimparted to screen 64. On the other hand, screen 65 at the moment shownin FIG. 3a is in the lifted position and receives such an additionalrotational movement.

To carry out the printing process shown in FIGS. 3a and 3b a deviceaccording to FIG. 4 is provided. In FIGS. 4 and 5 the two screens aredesignated by reference numerals 64 and 65, these screens printalternately according to the process described with reference to FIGS.3a and 3b. The lifting and lowering movements necessary for this processare obtained in the following manner.

Each screen assembly has a tooth detecting means 31 to detect thepassage thereby of each tooth of respective driving gear 24 and to emitimpulses representative thereof. In the specifically describedembodiment, the printing portion of screens 64 and 65 extendsubstantially over 80% of the screen circumferences, the remaining ofthe screen circumferences having the non-printing portions 66 and 67,respectively. The screen gears 77 fixed to the ends of the screens have108 teeth, and thus the length of the printing portion of each screencorresponds to approximately 86 teeth, and the length of the nonprintingportion of each screen corresponds to approximately 22 teeth. Thescreens will be adjusted as follows.

Screen 64 is turned to a position in which it is just about to contactthe material web 68 with the leading end 76 of the printing portion. Atthe same time counter-relay mechanism 82 for screen 64, similar tomechanism 33 described above, is set in a manner as will be describedbelow. with reference to the adjustment of screen 65. After the partialpattern 71 of screen 64 has been printed, the material web will bebrought under screen 65, and screen 65 will be turned by hand into aposition such that the leading end 75 of the printing portion of screen65 will coincide with the end 74 of partial pattern 71. Now,counter-relay mechanism 82 associated with screen 65 will be adjusted asfollows. A counter unit 78 is set to zero by a manual impulse applied toterminal 79 in a known manner. The A preset unit 80 is set to thedesired predetermined number, i.e., in the example, 216 2 X 108. Anothermanual impulse applied to load terminal 81 transfers the number 216 intothe counter 78. In subsequent printing, each tooth passing by toothdetecting means 31 of screen 65 creates an impulse which is conveyed viaamplifier 83 to the counter 78 to decrease the number contained thereinby one. The partial pattern 72 printed by screen 65 is simultaneouslyprinted onto the material web. When the end of the pattern 72 isreached, counter unit 84 and preset unit 85 are set in the same manneras described above in connection with counter unit 78 and preset unit80. Thus, counter 84 also initially contains the number 216. Eachfurther impulse fed by means 31 to counters 78 and 84 diminishes thenumberes contained therein by one. The flip-flop 86 is illustrated in aposition in which magnetic valve 87 effects a lifting of screen 65 bymeans of piston-cylinder assembly 88. The next impulse given to theflip-flop 86 switches the flip-flop such that, the next impulsetherefrom will shift magnetic valve 87 to cause lowering of screen 65.This next impulse arrives exactly after the counter 78 has registered216 impulses of the device 31. This, in turn, corresponds to exactly tworevolutions of screen 65. Therefore, after this number of impulsesscreen 65 is just about to again start printing, i.e., in a position inwhich it must be lowered. Now, when counter 78 reaches zero, an impulseis emitted at its output terminal 89, such impulse being sent, on theone hand, to the clear terminal 79, and on the other hand, to the inputor load terminal 81 of the preset unit 80. The clearimpulse sets counter78 to precisely zero, and the load impulse at the terminal 81 of presetunit 80 causes the same to again transmit the number 216 to counter 78.At the same time, the output impulse from terminal 89 of counter 78 istransmitted to flip-flop 86, causing the same to switch-over.Consequently, it gives via amplifier 90 and magnetic valve 87 a commandto pistoncylinder assembly 88 for lowering screen 65.

When screen 65 has finished its printing process, B- counter unit 84will reach Zero, and will emit an output impulse, whereby the counter 84will again be loaded with number 216. At the same time impulse isconveyed to flip-flop 86 which again will switch-over and in turn emitan impulse via amplifier 90 to the magnetic valve 87 to shift theposition thereof to cause pistoncylinder assembly 88 to lift screen 65.

The same cycle is effected in all elements associated with screen 64.However, there is of course a phase difference with respect to screen65.

Piston-cylinder assemblies 88 are fed with fluid such as oil by pump 91from reservoir 92. The fluid is pumped into either the upper or lowerchambers of the respective assemblies, as required at a given time, andout from the opposite chambers through magnetic valves 87 into thecollecting pipe 93 and therefrom into reservoir 92.

When each of the screens 64 and 65 are in their lifted position. anadditional rotary movement is imparted thereto by gear means 94. Forthis purpose, a secondary drive shaft 97 is driven by main drive shaft95 via gearing 96 including gears 103 and 104. Main drive shaft 95 anddrive gears 24 have a gear ratio of 1:1, i.e..

the rotational speed of drive shaft 95 is equal to that of drive gear24. However, this is only true for the periods during which noadditional rotary movement is imparted to the drive gears 24 by theMaltese-cross mechanism 98.

Drive shaft 95 carries worm or spiral gears 99 which each engage withworm or spiral gear 100, as shown in FIG. 5. Spiral gear 99 has twice asmany teeth as spiral gear 100, i.e., the rotational speed of spiral gear100 is the double of that of gear 99. Rotational speed of drive shaft 95is transmitted to planetary shaft 102 by a differential gear arrangement101. Spiral gear 100 is not keyed to shaft 102 but turns looselythereon. Shaft 102 extends from the left in FIG. and has fixed on theopposite end thereof drive gear 24, and carries transversal stub shaftsfor the two bevel gears 109 of differential gear arrangement 101. Also,gear 108 is not keyed or otherwise fixed to shaft 102. During theperiods in which no additional rotary movement is to be imparted todrive gear 24 which is fixed to shaft 102, element 108 remainsstationary, gear 100 rotates at the twice the normal speed, i.e., thespeed of drive shaft 95, and beveled gears 109 are rotated from the leftby spiral gear 100 at the double speed. Bevel gears 109 roll at theirright side on stationary gear 108. Thus, the centerlines, i.e., the stubshafts mentioned above, rotate at the normal speed. As the stub shaftsare fixed to shaft 102 the latter also rotates at the normal speed.

As mentioned above, each screen 64 and 65 must receive an additionalrotary movement once for each two revolutions thereof. This is achievedby Maltese-cross mechanism 98. One has to realize, however, that thesetwo revolutions must be brought about during a period of movement ofmaterial web 68 equal to the distance 63. This equals a rotation ofdrive shaft 95 corresponding to twice the number of teeth correspondingto the engraved circumference, i.e., 2 X 86 172 teeth. As the number ofteeth of drive gear 24 is 32, gear 103 must also have 32 teeth. However,gear 104 must have 172 teeth. Thereby it is achieved that the secondarydrive shaft 97 performs exactly one revolution for each two revolutionsof the screen, keeping in mind that an additional rotation is impartedto the screens, but not to shaft 97. By each revolution of secondarydrive shaft 97 the Maltese-cross 105 is turned through 90. This quarterof a revolution of Maltese-cross 105 must be sufficient to turn gear 24by twice the number of teeth (i.e., 22 teeth) corresponding to thenon-printing portion 66 or 67 of the circumferences of screens 64 or 65.For this purpose intermediate gearing 106 is provided which may be ofthe interchangeable type. The output of this gear is transmitted viaspiral gear 107 to gear 108 of the differential gear 101. In theembodiment described the total gear ratio between Maltese-cross 105 andbevel gear 108 of the differential gear 101 must be exactly 11. If so.gear 108 will perform exactly 2.75 revolutions on each quarterrevolution of the Maltesecross 105. Such 2.75 revolutions are halved bythe operation of differential gear 101, i.e., shaft 102 receives anadditional rotational speed which is half the speed of gear 108. Thus,shaft 102 performs 1.375 revolutions for each quarter revolution ofMaltese-cross 105.

As gear 24 has 32 teeth, 1.375 revolutions of thereof teeth (2 X 108)during a period of time corresponding to the movement of material web 68over a distance 63, corresponding to a rotation of drive shaft of 172teeth (2 X 86) or to the sum of the printing portions of thecircumferences of screens 64 and 65. It of course is to be understoodthat the precise gear ratios and number of screens employed in thespecific example of FIGS. 3-5 is intended to be exemplary only, and notlimiting to the scope of the invention.

Instead of lifting or lowering the printing cylinders, the contactbetween the latter and the material may also be effected or interruptedby lifting and lowering the transport or printers blanket supporting themate rial. Such arrangement is shown in FIG. 6. The printers table 133,e.g., including a magnet bar, is moved vertically by the hydrauliccylinder 123. The table slides in lateral guides 134, and a parallelconstruction (not shown) prevents tilting of the table. The toothed gearor disc is fixed to the same shaft as the drive gear, and initiates acontrol mechanism, in the same manner as described above with regard toFIGS. 2 and 4, for the control of cylinder 123.

In order to ensure proper lowering of the transport blanket togetherwith the printers table, the latter may be provided with vacuum chamberswhich suck the blanket down tightly to the surface of the table. It isfurther possible to arrange the printers tables such that the transportblanket has a polygonal shaft when pressed onto the tables. When singletables are lowered the blanket will rest on the upper surface of suchcorresponding table.

As already mentioned the invention is not limited to the examplesdescribed above. For instance, the additional rotation might be impartedto the individual repeat gears by a combination of a differential driveand a stepping motor which is switched on at the moment of maximum liftof the printing cylinder.

Further, it is to be understood that the various gear ratios discussedabove are intended to be exemplary only, and not limiting.

Still further, it is to be understood that the digital counter devicesneed not be the specific mechanisms 33 and 82 described above. Rather,such eevices may be any known type of electrical, mechanical orelectromechanical device which has memory capabilities and which is ableto receive impulses or signals in a digital manner and to emit a commandafter the receipt of a predetermined number of impulses.

In the above discussed specific embodiments, counters 34, 35, 78 and 84are integrated counter circuits, of which there are numerous on themarket. One such counter circuit is the Decade Counter SN. 7490manufactured by Texas Instruments. Also, presets 36, 37, 80 and 86 maybe of the known type of diode or transistor memory switch designated tomaintain or terminate current or voltage to a counter at predeterminedintervals. Further, flip-flops 47 and 86 may be any of the many knowntypes on the market. One such flip-flop is the Dual JK 7473 manufacturedby Texas Instruments.

It is to be understood that the above specific examples are not to beconsidered limiting to the scope of the invention. Many other types ofcomponents are equally employable, as will be understood by thoseskilled in the art. Many marketers of such components publish expansivebrochures and catalogs for the assembly of counter and memory controlcircuits.

Still further, those skilled in the art will understand that the abovediscussed counter and memory functions can equally be accomplished bymechanical devices, such ratchet arrangements.

I claim:

1. A rotary cylinder printing machine comprising:

a frame means providing a flat surface for supporting material to beprinted;

at least two printing devices supported on said frame means for printingsaid material, each of said printing devices including a rotary printingcylinder, each of said rotary printing cylinders having a firstcircumferentially extending printing portion and a secondcircumferentially extending nonprinting portion;

means for moving said material over said flat surface for sequentialcontact and printing by the first printing portions of the rotaryprinting cylinders of each of said printing devices;

driving means, operable by said means for moving, for continuouslyimparting a constant first rotary movement to the rotary printingcylinders of each of said printing devices and for thus rotating saidrotary printing cylinders at a first constant rotary speed equal to thespeed of said first rotary movement;

lifting device means connected to each of said printing devices and tothe respective adjacent portion of said flat surface for sequentiallymoving each of said rotary printing cylinders and the respectiveadjacent portion of said flat surface relative to each other, and forthus sequentially moving each of said rotary printing cylinders out ofcontact with said material;

means operatively connected to said driving means for indicating theangular positions of rotation of said rotary printing cylinders, withrespect to the respective positions of said first printing portions andsecond non-printing portions thereof;

means positioned to detect the indication of said angular positions andto transmit impulses representative thereof;

a separate digital counting means connected to said means to transmitand to each of said lifting device means for counting the number of saidimpulses from said means to transmit and for activating said liftingdevice means upon the counting of a predetermined number of saidimpulses, thereby moving each of said rotary printing cylinders and saidmaterial into and out of contact in a predetermined sequence dependentupon said angular position of respective of said rotary printingcylinders; and

additional rotation means, connected to said driving means, forimparting an additional second constant rotary movement to each of saidrotary printing cylinders only when out of contact with said material,and for thus changing the speed of rotation of each of said rotaryprinting cylinders to a second constant rotary speed. equal to the sumof the speeds of said first and second rotary movements, only when outof contact with said material.

2. A machine as claimed in claim 1, wherein each of said rotary printingcylinders comprises a rotary screen; each of said first printingportions comprises a circumferential length of said respective screenhaving perforations therein; and each of said second non-printingportions comprises a circumferential length of said respective screenhaving no perforations therein.

3. A machine as claimed in claim 1, wherein said driving means comprisesa cylinder gear fixed to each of said rotary printing cylinders, a driveshaft mounted on said frame, and a separate drive gear meshing with eachof said cylinder gears for driving each of said rotary printingcylinders and connected to said drive shaft.

4. A machine as claimed in claim 3, wherein said additional rotationmeans comprises a supplemental drive shaft mounted on said frame; gearmeans interconnected between said drive shaft and said supplementaldrive shaft for imparting rotation to said supplemental drive shaft; adifferential gear mechanism interconnected between said drive shaft andeach of said drive gears; and means interconnected between saidsupplemental drive shaft and each of said differential gear mechanismsfor supplying said second constant rotary movement to each of saidrotary cylinders.

5. A machine as claimed in claim 1, wherein said lifting device meanslift said rotary printing cylinders toward and away from said material,from a first position in contact with said material to a second positionout of contact with said material.

6. A machine as claimed in claim 1, wherein said lifting device meanslift said material toward and away from said rotary printing cylinders.

7. A machine as claimed in cliam 1, wherein said further additionalrotation means comprises a supplemental drive shaft mounted on saidframe; gear means interconnected between said driving means and saidsupplemental drive shaft for imparting rotation to said supplementaldrive shaft; and means interconnected between said supplemental driveshaft and each of said driving means for supplying said second constantrotary movement to each of said rotary cylinders.

8. A machine as claimed in claim 1, wherein each of said lifting devicemeans is a fluid operated pistoncylinder mechanism; and each of saiddigital counting means comprises an electronic counter-relay mechamsm.

1. A rotary cylinder printing machine comprising: a frame meansproviding a flat surface for supporting material to be printed; at leasttwo printing devices supported on said frame means for printing saidmaterial, each of said printing devices including a rotary printingcylinder, each of said rotary printing cylinders having a firstcircumferentially extending printing portion and a secondcircumferentially extending nonprinting portion; means for moving saidmaterial over said flat surface for sequential contact and printing bythe first printing portions of the rotary printing cylinders of each ofsaid printing devices; driving means, operable by said means for moving,for continuously imparting a constant first rotary movement to therotary printing cylinders of each of said printing devices and for thusrotating said rotary printing cylinders at a first constant rotary speedequal to the speed of said first rotary movement; lifting device meansconnected to each of said printing devices and to the respectiveadjacent portion of said flat surface for sequentially moving each ofsaid rotary printing cylinders and the respective adjacent portion ofsaid flat surface relative to each other, and for thus sequentiallymoving each of said rotary printing cylinders out of contact with saidmaterial; means operatively connected to said driving means forindicating the angular positions of rotation of said rotary printingcylinders, with respect to the respective positions of said firstprinting portions and second non-printing portions thereof; meanspositioned to detect the indication of said angular positions and totransmit impulses representative thereof; a separate digital countingmeans connected to said means to transmit and to each of said liftingdevice means for counting the number of said impulses from said means totransmit and for activating said lifting device means upon the countingof a predetermined number of said impulses, thereby moving each of saidrotary printing cylinders and said material into and out of contact in apredetermined sequence dependent upon said angular position ofrespective of said rotary printing cylinders; and additional rotationmeans, connected to said driving means, for imparting an additionalsecond constant rotary movement to each of said rotary printingcylinders only when out of contact with said material, and for thuschanging the speed of rotation of each of said rotary printing cylindersto a second constant rotary speed, equal to the sum of the speeds ofsaid first and second rotary movements, only when out of contact withsaid material.
 2. A machine as claimed in claim 1, wherein each of saidrotary printing cylinders comprises a rotary screen; each of said firstprinting portions comprises a circumferential length of said respectivescreen having perforations therein; and each of said second noN-printingportions comprises a circumferential length of said respective screenhaving no perforations therein.
 3. A machine as claimed in claim 1,wherein said driving means comprises a cylinder gear fixed to each ofsaid rotary printing cylinders, a drive shaft mounted on said frame, anda separate drive gear meshing with each of said cylinder gears fordriving each of said rotary printing cylinders and connected to saiddrive shaft.
 4. A machine as claimed in claim 3, wherein said additionalrotation means comprises a supplemental drive shaft mounted on saidframe; gear means interconnected between said drive shaft and saidsupplemental drive shaft for imparting rotation to said supplementaldrive shaft; a differential gear mechanism interconnected between saiddrive shaft and each of said drive gears; and means interconnectedbetween said supplemental drive shaft and each of said differential gearmechanisms for supplying said second constant rotary movement to each ofsaid rotary cylinders.
 5. A machine as claimed in claim 1, wherein saidlifting device means lift said rotary printing cylinders toward and awayfrom said material, from a first position in contact with said materialto a second position out of contact with said material.
 6. A machine asclaimed in claim 1, wherein said lifting device means lift said materialtoward and away from said rotary printing cylinders.
 7. A machine asclaimed in cliam 1, wherein said further additional rotation meanscomprises a supplemental drive shaft mounted on said frame; gear meansinterconnected between said driving means and said supplemental driveshaft for imparting rotation to said supplemental drive shaft; and meansinterconnected between said supplemental drive shaft and each of saiddriving means for supplying said second constant rotary movement to eachof said rotary cylinders.
 8. A machine as claimed in claim 1, whereineach of said lifting device means is a fluid operated piston-cylindermechanism; and each of said digital counting means comprises anelectronic counter-relay mechanism.